Question

Without using a calculator evaluate:
- 81 + 203²

Answer 1

Explanation:

multiply 203 by 200, you get 20300 and then multiply the 3 and you get 20909. Then subtract 81 from it and you have 20828 as the final answer.

Answer 2

• 41128

Explanation:

This problem requires the formula "a² + 2ab + b²".

• -81 + 203²
• => -81 + (200 + 3)²
• => -81 + (200² + 2(200)(3) + 3²)
• => -81 + (40000 + 1200 + 9)
• => -81 + (41209)
• => 41209 - 81
• => 41128

Hence, 41128 is the answer without using calculator.